Vanguard Instruments EZCT Use and care manual

INSTRUCTION TO CALIBRATE THE EZCT
1. Please upgrade the firmware of the EZCT to the latest version.
2. Using windows XP to create a Hyper Terminal connection for communication
between the computer and the EZCT.
Please see the picture from below to set the following conditions when creating
Hyper Terminal Connection:
3. Once the connection is established, please connect the EZCT to the computer
using the RS-232 cable.
4. Turn on the EZCT, and Press “4,8” on the keypad of the unit. At this point, the
Hyper Terminal Connection should display as shown below:

5. Select “A” to calibrate the unit. Please do not select any other options as it
may damage the unit internally.
6. It is extremely critical to follow the instruction on the screen at all time.
7. The first step is to calibrate the “X RMS Sense”. Please see the picture for
connection between the EZCT and the Fluke Meter. Do not connect the H-cable.
8. Please turn the controlled knob on the front panel of the EZCT and set the voltage
around 750VAC. Once the voltage is set around 750 VAC, please enter the
voltage value within one decimal as seen in the volt meter. Please see picture
below as reference:

9. Please note the “X RMS Scale” should be around “C80h”
10. The next step is to calibrate the “X-Ratio Sense” and “H-Ratio Sense”. Please
follow the instruction on the screen for properly hook-up and then increase the
voltage up to 10VAC.
11. Using the picture below for reference. Notice “X Ratio” and “H Ratio” are
approximately “B800h” and “C400h” respectively.
12. The next step is to calibrate the “Current RMS Sense” at 1A using 15 ohm, 50W
resistor in series with the Current Fluke meter to X1-X2 cables. Please see the
picture for connection.

Notice “I RMS Scale” is around “220h” at 1A.
13. At this point, press any key to complete the calibration.
14. Press “ESC” to terminate the serial diagnostic menu.